The present invention relates to an elastomeric polyurethane polymer arrow vane. In particular, the present invention relates to an arrow vane with a tapered fletch produced in a manner which gives it true flight characteristics because of freedom from wrinkles in the fletch.
The elastomeric polyurethane polymers have very desirable flexibility which make them an ideal material for use in arrow vanes. In order to form vanes from these polymers, the prior art has extruded a ribbon which forms a V shaped base with a flat, uniform rectangular cross-sectioned extension from the point of the V. After extrusion, the vanes are die-cut from the ribbon which forms the conventional curved fletch from the extension.
There are problems with die-cut vanes. First, the fletch is relatively thick at its outer edge opposite the base, second there is non-uniformity of the fletch and base because of the extrusion and cutting and third the vane surfaces are shiney which can frighten game if reflected in the sunlight.
Injection molding is a desirable and less expensive means of forming the vanes since a thin taper can be imparted to the fletch. Second, the mold surfaces can be treated to have minute projections which mat the surfaces of the vane. Third the vanes are very uniform. The problem with injection molding is that the base curves in the direction top of the V corresponding to the outer curvature of the fletch after removal from the mold due to stresses from molding. This produces wrinkling or warping of the fletch when it is attached to the arrow shaft. The result is most evident when a single molding gate leading into the base of the fletch is used, which is the easiest, most economical and reproducible method of producing vanes which are well formed.
It is therefore an object of the present invention to provide an elastomeric polyurethane polymer vane which will not warp or wrinkle when attached to the arrow shaft. It is also an object of the present invention to provide a method for producing the vanes which is simple, economical and reproducible. These and other objects will become increasingly apparent by reference to the following description and the drawings.